This invention relates to methods of injecting tin-containing antifoulants into thermal cracking (pyrolysis) reactors, so as to alleviate the undesirable formation of coke and carbon monoxide during thermal cracking of light hydrocarbons. In a particular aspect, this invention relates to injecting tin-containing antifoulants into ethane cracking reactors (for making ethylene).
Numerous tin-containing antifoulant agents for reducing the formation of coke on the metal walls of light hydrocarbon pyrolysis (thermal cracking) reactors are known and have been described in the patent literature, such as U.S. Pat. Nos. 4,404,087, 4,507,196, 4,545,893, 4,551,227, 4,552,643, 4,666,583, 4,687,567, 4,692,234 and 5,015,358. These tin-containing antifoulants (either dissolved tin compounds or mixtures of dissolved tin and other compounds) can be injected into a hydrocarbon-containing feed, or they can be used to pretreat (coat) the inner metal walls of a thermal cracking reactor (before the hydrocarbon-containing feed is introduced into the cracking reactor), or both. The present invention is directed to novel methods of injecting tin-containing antifoulants into thermal hydrocarbon cracking reactors, either before or during the thermal cracking of hydrocarbons, so as to alleviate the deposition of coke on metallic reactor walls and the generation of carbon monoxide.